The invention relates to a rack and pinion jack for lifting, lowering and/or supporting containers, shelters or the like, wherein the engagement parts of two crosspieces cooperate with the corner metal fittings of the containers, which crosspieces, arranged on the cranking shaft at some spacing from one another, are associated with the top and/or bottom corner metal fittings, whereby the engagement part for the top corner metal fittings is arranged parallel to the cranking axis and the engagement part for the bottom corner metal fittings is arranged perpendicular to the cranking axis.
A rack and pinion jack of the aforementioned structural type is already known from U.S. Pat. No. 4,045,000. In this rack and pinion jack the top crosspiece is fastened at the top end of the cranking shaft and has a rod extending outward at a right angle to the cranking axis, at the outside end of which is arranged the engagement part for the top corner metal fittings of the container. This known rack and pinion jack is also suitable for handling containers of different heights, but operates within the limitation that the height of the container may not exceed the height of the rack and pinion jack in its initial state. In other words, said known rack and pinion jack is not suitable for containers which are of greater height than the rack and pinion jack in its initial state. At this point it is to be noted that the structural height of such rack and pinion jacks cannot be increased arbitrarily, because these rack and pinion jacks must be able to be stored in horizontal position following use, usually on the front wall of the container in suitable known holders. Thus the rack and pinion jacks may not project out to the side over the front walls of the container. The traditional breadth of the container is 8', and consequently the structural height of the rack and pinion jack in retracted state is also limited to this dimension. Now however for practical reasons containers are presently being used which even when they have the identical breadth of 8' have a greater structural height, and for these, as explained above, the known rack and pinion jack is not suitable. For this purpose then, longer special embodiments of rack and pinion jacks would be required, which are correspondingly more costly.